Traffic actuated device



Nov. 17 1936 A o (IJLAFF5QN 2,$6@,890

TRAFFIC ACTUATED DEVICE Filed Oct. 13, 1933 2 Sheets-Sheet l Nov. 17, 1936." O QLAFSQN 2,060,890

TRAFFIC ACTUATED DEVICE Filed Oct. 13, 1933 2. Sheetsksheec 2 Patented Nov. 17, 1936 UNITED. STATES PATENT OFFICE TRAFFIC ACTUATED DEVICE Alvin 0. Olafson, St. Paul, Minn., assignor to National Trafiic Signal Company, St. Paul, Minn., a corporation of Minnesota Application October 13, 1933, Serial No. 693,475

4 Claims. (01. Bil-62.6)

This is a traffic actuated device for a switch virtually little orv no attention and that the strucdesigned to be operated by traflic in a highway, ture be so simple that there are no working parts primarily vehicles which pass over the same, opwhich will be inclined to get out of order or erating the device so that other devices such as which will not be durable for a long period of 5 signals, or other means, may be operated by the time, and while I have accomplished this in my 5 operation of this device. structure, nevertheless, I have provided a unitary A feature resides in providing a unitary pad means to the respective major elements so that having a resilient P t which i ad pt t b they may be readily replaced, as well as making held in elevated position by a series of flat bronze it more easy to assemble them or us The springs which extend beneath the resilient memtraffic actuated switch operates positively to close 10 her and tend to arch it up from-the base when a circuit controlled by the same, and thus in turn it is free. the circuit may be employed for any desired pur- A further feature is in providing a unitary pose and is ideally practical for-controlling sigpad which may be easily replaced in its entirety nailing devices.

and wherein means is provided to compensate for In the drawings: 15 expansion and contraction of the same. The Figure 1 illustrates a plan view of my traflic removable means includes anchoring members actuated device and a switch as it would appear for holding the unitary pad in operative position. placed in the pavement of a highway.

Further, the device includes the co-ordinating Figure 2 is a longitudinal section on the line mechanism of a diaphragm which is controlled 2-2 of Figure 1, through the pad and through 20 by the pad and which is adapted to operate an the protecting casing of the switch, showing the electric switch to close a circuit, the purpose of same therein. which will be set forth. Figure 3 is an enlarged section on the line 3-3 A feature resides in providing a housing for of Figure 1. I protecting the diaphragm in its unitary construc- Figure 4 is an enlarged section detail of a 25 tion and also'shielding it from moisture, so that portion of the pad. it will function most efficiently at all times. Figure 5 is a plan detail of a portion of the pad. The device includes a diaphragm structure Figure 6 is an enlarged section through the which limits the movement of the diaphragm in diaphragm unit and switch, with the housing for its operation so that it will not be unduly strained containing the same. 30

or expanded even though the pad which operates Figure 7 is a section on the line 1-1 of Figure 6.

it may force a rush of air to the same beyond This traffic actuated device includes a unitary that which is ordinarily necessary to operate traflic operated pad A which is connected by the the diaphragm. pipe In to a diaphragm switch operating unit B,

The diaphragm has means of causing the terand the unit B is inclos'ed within the protective 35 minals of an electric switch to be closed, moving housing II. The pad A and the unit B are emthe terminals with a wiping action which keeps bedded within the highway or may be set up and .the contacts clean, and the structure of the associated together in any suitable manner, de-

diaphragm casing being formed to support shoulpending upon the purpose for which they are 40 der means which are adapted to separate the desired to be used. 40 electric contacts as the diaphragm recedes out In the form of the traffic actuated switch illusof operative position. The diaphragm structure trated, the pad A is of a unitary structure having also is provided with a relief and atmospheric a comparatively strong longitudinally extending opening which relieves any excess rush of air base plate l2, the ends l3 of which project to to the diaphragm as well as connecting the diaform a shoulder for engaging with the anchoring phragm with the atmosphere, permitting it to plates M which in turn are secured to the anchor recede out of switch operating position more bolts 15 buried in the pavement so as to secure quickly. the ends of the pad A in a manner so that the A further feature of the invention resides in same may be removed by disengaging the plates providingatrafiic actuated pad made in aunitary I4. A space for expansion and contraction is 5 form so that it may be readily replaced, as well provided between the shoulder ends l3 and the as providing a diaphragm unit which may also be anchoring means I 4 and I5. readily and quickly replaced when it is desired, The pad A is provided with a heavy rubber or if it is necessary. In devices of this character sheet covering I6 which may be formed with a it is essential that they operate positively with fabric reinforced body portion l1, while the up- I A per outer surface I8 is of strong durable rubber. The reinforced fabric may be similar to the rubber embedded and treated cords of an auto mobile tire, thereby providing a more resilient and durable covering IS. The covering I6 is adapted to be clamped marginally by the anchoring plates H! which are held by the screws 20 to the base plate l2. The center of the covering I6 is adapted to be held arched above the central portion 2| of the plate l2 by a series of adjacent bronze spring plates 22. It is apparent that these spring plates may be made of other suitable similar material.

The spring plates 22 extend from one side to the other of the pad A and have hook ends 23 which are adapted to engage against the inclined shoulder 24 formed longitudinally in one side of the groove 25 which extends longitudinally on each side of the bed plate l2.

When the cover N5 of the pad A is held arched in the position illustrated in Figure 3, by the springs 22, the hook ends 23 are engaging against the shoulders 24, however, as soon as a vehicle starts to pass over the covering l5, say in the direction of the arrow illustrated in Figure 3, the spring plates 22 will flatten down against the inner surface 2| of the plate l2, with the near hook end 23 engaging the shoulder 24, while the far end with the hook end 23 of the plates 22 over which the vehicle wheels are moving, will move in the slot 25 so as to permit the spring 22 to flatten without buckling. If the traflic moves over the pad in the opposite direction, the parts will work in the same manner, thereby permitting the covering IE to be flattened down and without wrinkling of the springs 22. By placing a series of spring plates 22 in position, as illustrated in Figure 1 in dotted outline, under the rubber covering |6, different sections of the pad A may be travelled over without wrinkling, and even though a vehicle wheel stopped on one portion of the pad, another free portion could be travelled over by a vehicle, causing the pad to operate, as will be later set forth.

When any portion of the pad A is depressed by a vehicle wheel travelling over the same, the air between the surface 2| and the arched pad covering l8 may be forced from one of the grooves 25, as illustrated in Figure 5, out of the hole 26, and through the pipe ID to the diaphragm switch operating unit B. The channels 25 maintain a free passageway for the air from under the covering IE to the opening 26 and through the pipe In to the diaphragm unit B. Thus as a, vehicle wheel passes over the pad A, air is rushed to the diaphragm unit B.

The diaphragm unit B is adapted to be inclosed in the housing II which is formed with a central tubular portion 29 to which the pipe In connects and which is adapted to support one side 30 of the casing in which the flexible diaphragm 3| is supported. The flexible diaphragm 3| normally curves toward the substantially flat portion 32 of the casing portion 38 and is adapted to be marginally secured thereto by the marginal edge 33 of the upper washer-like covering disc 34 which is held by the screws 35 to the rim of the portion 32.

The flexible diaphragm 3| may be formed of any suitable material and I anchor a switch operating stud 33 to the center thereof by means of clamping washers 31 which extend on either side or the diaphragm 3|. The stud 33 normally extends through the opening 38 in the cover disc 34 in a position to operate against the free ends 38 and 40 of the electric switch 4|.

The free ends 39 and 4|] of the electric switch 4| are normally held spaced apart by the insulating shoulders 42 and 43. The shoulders 42 and 43 are supported projecting from the cover disc 34 and are adjacent the opening 38. The ends 38 and 40 are provided with electric contacts 44 and 45, respectively, which are spaced apart when the ends 39 and 40 are spaced by the shoulders 42 and 43, as illustrated in Figure 6. Thus in this position the electric switch 4| is open, however, the stud 36 is in position extending through the opening 38 ready to lift the ends 39 and 40 01! of the shoulders and thus closing the contacts 44 and 45 against each other with a wiping action. The wiping action of the closing of the contacts 44 and 45 is due to the spring arm which make up the switch 4| and which are anchored to either side of the insulating bar 48 which is secured to the bracket 41. The bracket 41 is supported on the edge of the diaphragm by some of the screws 35, as illustrated in Figure 7. Leading from the respective arms of the switch 4| an electric terminal 48 is provided for the upper arm of the switch 4| which carries the contact 44 while the arm which carries the lower contact 45 is provided with a terminal 49 which is insulated by the insulating washers 50 from the other arm of the switch 4|. Thus the terminals 4B and 49 provide a means of attaching the electricwires 5| that lead from the switch 4| to any device adapted to be'operated by the switch 4|.

The wires 5| leading from the respective torminals 48 and 49 may extend through the conduit 52 out of the casing The casing is provided with a cover 53 which is held in position to close the casing by the screws 54 and suitable radial reinforcing ribs 55 extend from the axis 55 of the cover 53 toward the outer edge. These ribs reinforce the cover to make it strong and durable so that traffic may pass freely over the same.

Extending from the axis 56 of the cover on the inside thereof, I provide a moisture hood 51 which projects beyond the limits of the outer diameter of the unit B and is provided with a non-metallic bottom portion 58 which is secured to the hood portion 51 by clip ends 59, thus providing an air space between the hood 51 and the bottom 58 so that no moisture will be carried from the cover 53 down against the unit B. This is important because in different atmospheric conditions, if any moisture would run down and drip off of the cover 53 against the unit 13, it might impair the operation of the same. The hood 5! may be secured to the inside of the cover 53 by the screw 50. The hood forms an important means of protecting the unit under all weather conditions.

In operation my traffic actuated switch is controlled by the pad A so that when a vehicle passes over the pad the air in the same will be rushed instantly to the diaphragm unit B, causing the diaphragm 3| to elevate the stud 36 in a manner to close the switch 4|. The closing and opening of the switch 4| takes place with a slight wiping of the contacts 44 and 45 owing to the fact that the arms which carry the same extend angularly from the outer edge of the diaphragm B toward the stud 35 and as the arms of the switch 4| are raised off of the shoulders 42 and 43, the contacts 44 and 45 close against each other with a wiping action and separate in the same manner. This keeps them clean and operative at all times.

The closed side of the diaphragm which connects with the pipe i0 is provided with a small air jet 62which relieves any excess rush of air to the diaphragm 3| as well as connecting the closed side of the same with the outer atmosphere, thereby permitting the diaphragm to recede into the position illustrated in Figure 6, after a rush of air has elevated it to close the switch 4|. On the other hand, after a large rush of air is forced to the diaphragm 3|, it will raise up against the washer-like cover 34 which limits the movement of the diaphragm 3| and prevents any damage or any undue stretching thereof. This forms a simple diaphragm unit switch B which operates continuously and has no delicate parts which might easily get out of order or fail to operate. In traflic signals it is essential that the diaphragm switch unit B, as well as the pad A, operatewithout failure and whenever the traflic passes over the same where it is desirable for this traflic actuated switch to operate signalling devices at intersections of highways. The trafiic actuated switch must operate under all kinds of weather conditions and so long as the pad A is free to be operated by the traffic, it will continue to operate and force suflicient air to the diaphragm of the unit B to close the switch II. It will also be apparent that even though pressure is exerted against one section of the pad A and a vehicle travels over another portion, there will be suflicient air carried to the diaphragm switch to close the same, each spring 22 providing an independent action and causing the pad to be raised by these sectional springs. The jet 62 relieves the diaphragm after it has closed the switch 4|, and thus the remaining portion of the pad A which is not being pressed down by anything bearing on the same, would be active to cause the diaphragm to operate the switch again when anything passed over the active portion of the pad A.

The springs 22 have sufiicient tension to cause the ends 23 to 'be held normally with tension against the shoulders 24, while the central portion of the spring 22 bears with tension against the flexible cover IE to hold it elevated. This makes the pad A very active and permits the springs 22 to flatten down against the surface 2| when a load bears down on the flexible cover I 6.

The jet 62 compensates for the change in atmospheric conditions so as to keep the diaphragm 3| unaffected by the change in atmospheric con ditions, including hot and cold weather, permitting the diaphragm to recede into its normal inactive position inclining along the flat portion 32 of the casing 30, and not operated or moved into different positions owing tothe change of atmosphere or temperature. Thus the setting of the diaphragm always remains the same. This permits the switch 4| to be accurately'operated because it does not change the position of the diaphragm 3i under varying atmospheric conditions and this is an important feature of my diaphragm switch.

The air in the pad is maintained in accordance with the atmospheric conditions by the connection with the diaphragm chamber and the jet 62 which performs an important function in maintaining the parts always set' to operate accuratelywithout distortion. Further, while the unit B is sealed within the housing Il so as to protect the same, it is connected to the outer atmosphere by the conduit 52 which carries the wires 5| to the outer atmosphere up out of the pavement of the highway.

There are various uses for a device of this chalracter which is simple, positive, virtually instant, and designed to operate automatically without attention. The invention should be considered with the broadest interpretation of the appending claims wherein a structure of this character is operated by the means defined or their equivalent.

I claim:

1. A traflic actuated pad including, a base member, a series of springs bowed between the side edges thereof and mounted under tension in said base member, a flexible covering for said base member adapted to be held bowed by said springs away from said base member to provide an air pocket therebetween, marginal gripping means adjacent the side edges of the spring for attaching said flexible covering to said base member and an air pocket through which air may be forced in the actuation of the pad.

2. A traflic actuated pad including, a base, longitudinal recesses formed along the upper surface of said base, shoulders formed in said recesses, flat springs having hook ends adapted to engage said shoulders under tension with the body of said springs bowed upwardly away from said base, a flexible covering extending over said base against the tension of said springs, means for clamping said covering to said base and an air pocket through which air may be forced in the actuation of the pad.

3. A traiflc actuated pad including a base adapted to be secured in a roadway, a pair of spaced parallel grooves in said base, a flat upwardly bowed spring on said base extending between said grooves, flanges on the edges of said spring extending into said grooves, an air outlet in said base, and a flexible covering over said spring and base secured marginally to said which air may be forced in the actuation of the,

pad.

ALVIN O. OLAFSON. 

